1. Field of the Invention
The invention relates to a support for a system for fastening a rail on a substrate with an angle bracket, which has a base section with a contact surface associated with the respective substrate, with a supporting section standing on the base section, which on its free front side, associated with the rail to be fastened, has a bearing surface, and also having a through hole formed in the base section for inserting a fastening element intended for fixing the angle bracket on the substrate.
Furthermore the invention relates to a system for fastening a rail on a substrate with a guide plate for lateral support of the rail to be fastened, with a spring element, which is supported on the guide plate and having at least one spring arm, which is provided to exert a flexible retaining force onto the foot of the rail, comprising means for tightening the spring element as well as a support, which is intended to be firmly connected to the substrate and in the assembled position to support the guide plate against transverse forces arising when the rail is driven over.
2. Description of the Related Art
A support and a system of this type are known for example from the German Patent DE-AS 26 00 416.
The known systems in particular serve for fastening rails on a rigid level substrate, wherein no recesses are formed or no elevations are embodied, on which the rail could be supported against the transverse forces arising at the corresponding fastening point when the rail is driven over.
Rigid substrates, on which systems of the inventive type are installed, in practice are also designated “rigid track bed”. In contrast to a track structure built on loose ballast they do not possess any intrinsic flexibility. Typically rigid track beds are formed from concrete slabs, on which sleepers likewise cast from concrete are laid, which in turn support the rails.
The rails are usually laterally supported on such a rigid substrate by supporting devices, which are positioned on both sides of the rail foot between the rail foot and possibly a shoulder arranged laterally at a distance from the rail foot. This shoulder is usually provided for this purpose on the respective rigid substrate in the form of a support shoulder or the like.
Thus the concrete sleepers typically used for fastening rails on a rigid track bed usually have lateral shoulders, against which the guide plates provided for lateral guidance of the respective rail are supported. These guide plates are fixed either directly on the rigid substrate or the individual sleeper by means of suitable fastening devices, usually bolts. A corresponding system is known in practice for example under the reference “300 system”.
Usually the fastening devices are also used for clamping a spring element, which exerts a retaining force, directed at the rigid substrate, onto the foot of the rail to be fastened. Dependent on the nature of the substrate and the fastening devices used, additional mountings and fastenings are needed for correct alignment and support of the rails. On track bed surfaces, which are level, that is to say where there are no shoulders for lateral support of the guide plates, fastening systems of the type described above cannot be used. Instead supports, as described in DE-AS 26 00 416 already mentioned, are needed there.
The main requirement for the correct functioning of a fastening system of the type detailed above is that the rail is laterally supported in a manner, which is substantially free from play. Relative movements between the rail and the substrate, on which it stands as the case may be, would otherwise cause substantial abrasive wear in the supporting section of the rail foot.
In order to meet this requirement the support used in the known system comprises an angle bracket, which is fixed on the respective substrate by means of a fastening bolt, inserted through the opening formed in its base section. The bearing surface, associated with the guide plate, of the angle bracket is therefore inclined.
On the inclined bearing surface of the angle bracket the guide plate of the known fastening system lies in close contact with a correspondingly inclined supporting surface, whereby an insulating layer may be provided between the bearing surface and the supporting surface, in order to ensure electrical insulation between the angle bracket and the guide plate. At the same time the guide plate, with its bearing surface associated with the rail possibly likewise laterally lies in contact with the rail foot via a correspondingly insulating intermediate layer.
The guide plate is likewise fastened on the respective substrate in the known system by a bolt inserted in a corresponding through hole, which in the case of fastening on a rigid track bed is screwed for example into a dowel set into the substrate. In this case not only the guide plate is held, but also the tension clamp is tightened by means of a nut screwed onto the bolts, which exerts the necessary retaining force onto the ribbed plate.
A problem with fastening rails in the way described above, known from DE-AS 26 00 416, is that it does not allow precise alignment of the individual parts constituting the fastening. This relates in particular to the relative position of guide plate and angle bracket.
Practical experience has shown that such precise positioning, under the conditions prevailing in practice, frequently cannot be guaranteed with the necessary reliability. This applies in particular if a large number of fastenings of this type are to be assembled in a mass operation so as to be able to save time when laying long sections of track.